One issue that is difficult to
resolve is how to order the list of
languages or countries.
You
could use the Unicode Collation Algorithm,
sort by population size or GNP, sort by BCP
47 language tags, etc. to be neutral,
although many users would possibly not
understand the rationale for such
ordering.

For
country-specific links it
may help to use maps of regions to narrow
the search to a list that may be easier to
scan.